Project III tests the general hypothesis that patterns of low-level information processing will be systematically associated with clinical manifestations of learning disorders. We will determine whether interindividual differences among LD children, based on patterns of performance on measures of low level information processing (LLIP), are systematically associated with clinical test performance. Learning disabled children (N = 200) will be examined on standard and clinical profile measures of neurodevelopmental status and neuropsychological function, as well as on measures of oral and written language and mathematics competence. LLIP profiles, as ascertained in Project I, will be examined for their association with specific features of the clinical presentation. A secondary aim is to determine whether neurobehavioral profiles, as ascertained by neurological and neuropsychological assessment, are associated with each other and with characteristic pattern of academic expression.